Clinical Medical Assisting Chapter 14: Nervous and Sensory Systems

Objectives Identify combining word forms of the nervous system and their role for the formation of medical terms Define the structures and functions of the nervous system Identify common diseases, diagnostic procedures, and their treatment Identify combining word forms of the special senses and their role for the formation of medical terms Define the structures and functions of the special senses

Objectives (con’t) Differentiate between instillation and irrigation Discuss the different types of visual acuity charts and how to use them appropriately Explain the medical assistant’s role when assisting with audiometry List items required by a provider for a neurologic examination and explain the medical assistant’s role in the examination Define a cerebral vascular accident (CVA)

Chapter Overview This chapter covers the basics of medical terminology related to the nervous system and the special senses. It includes a description of the nervous system and coverage of the special senses along with common diseases, diagnostic procedures, and treatment.

The Nervous System The nervous system has two main divisions: the central nervous system (CNS) and the peripheral nervous system (PNS).

The Central Nervous System The central nervous system includes the brain and spinal cord.

The Brain The brain is the control center of the body.

Meninges The brain and spinal cord are protected by three connective tissue layers collectively called the meninges.

Cerebrospinal Fluid Acts as a cushion, protecting the brain and spinal cord from injury.

Diagnostic Tests Diagnostic tests and procedures are vital tools that help doctors confirm or rule out the presence of a neurological disorder or other medical condition.

X-Rays X-rays of the patient’s skull are often taken as part of the neurological work-up.

Cerebral Angiogram Can detect the degree of narrowing of an artery or blood vessel in the brain, head, or neck.

Brain Biopsy Involves the removal and examination of a small piece of tissue

Brain Scan Imaging techniques used to study organ function, injury, and disease, and to diagnose tumors, blood-vessel malformations, and hemorrhage in the brain

Cerebrospinal Fluid Analysis Analysis involves the removal of a small amount of the CSF by lumbar puncture or spinal tap.

Computed Axial Tomography Computed tomography (CT or CAT scan) is used to produce rapid, clear images of organs, bones, and tissues.

Intrathecal Contrast-Enhanced CT Scan Detects problems with the spine and spinal nerve roots

Electroencephalography Monitors brain activity through the skull

Electromyography Used to diagnose nerve and muscle dysfunction and spinal cord disease

Electronystagmography Used to diagnose involuntary eye movement, dizziness, and balance disorders, and to evaluate some brain functions

Evoked Potentials Measures the electrical signals to the brain generated by hearing, touch, or sight

Magnetic Resonance Imaging Uses computer-generated radio waves and a magnetic field to produce detailed images of body structures, including tissues, organs, bones, and nerves

Myelography An X-ray examination of the spinal canal

Positron Emission Tomography Provide two- and three-dimensional pictures of brain activity by measuring radioactive isotopes that are injected into the bloodstream

Neurosonography Analyzes blood flow in the brain

Videonystagmograph A special examination that measures eye movements and is used to evaluate balance

Diseases and Disorders A disease of the nervous system can affect the brain or spinal cord.

Alzheimer’s Disease A degenerative disorder of the brain that leads to loss of brain function

Amyotrophic Lateral Sclerosis Known as Lou Gehrig's disease

Bell’s Palsy A disorder of the nerve that controls movement of the facial muscles

Encephalitis A severe inflammation of the brain that can destroy nerve cells, cause bleeding in the brain, and result in brain damage

Epilepsy A neurological condition that is also known as a seizure disorder

Meningitis An inflammation of the membranes that cover the brain and spinal cord

Parkinson’s Disease A motor-system disorder caused primarily by progressive degeneration of dopamine-containing neurons in the substantia nigra, which is the layer of gray substance in the brain

Sensory Systems There are five major senses: sight, hearing, touch, taste, and smell.

The Eyes Eyes perceive images and translate them into impulses

The Ears Ears are responsible for hearing and maintaining balance

The Nose The olfactory organ at the top of the nasal cavity is responsible for the sense of smell

The Tongue Receptors on the tongue give us the ability to taste different flavors

Diseases and Disorders of the Eye The location and exposure of the eye make it susceptible to contamination and infection.

Age-Related Macular Degeneration Age-related macular degeneration (AMD) is a disease that affects the macula and causes loss of central vision.

Blepharitis Blepharitis is an inflammation of the edges of the eyelids.

Cataract A condition in which the normally clear lens of the eye becomes cloudy

Diseases and Disorders of the Ear Disorders of the ear are common, and range from pain (otalagia), to excess wax in the ear canal, to complicated infections.

Eye Examination Visual examinations may need to be performed if a patient has an eye injury or an infection, or as a screening to check visual acuity.

Ear Examination Auditory acuity may also be measured as part of the physical examination.

Neurological Examination A neurological examination assesses motor and sensory skills, hearing, speech, vision, coordination, mental status, mood, behavior, memory, and cognition.

Cerebral Vascular Accident Commonly known as a stroke or brain attack

Summary Medical assistants must have a good working knowledge of medical terminology. The central nervous system (CNS) is the body’s control center and includes the brain and spinal cord. The peripheral nervous system (PNS) includes all the nerves that connect the CNS to every organ and area of the body. It includes 12 pairs of cranial nerves that connect the brain directly to the sense organs, the heart, the lungs, and other internal organs. It also includes 31 pairs of spinal nerves.